Rotary device with access port



May 29, 1962 E. F. PETERSON 3,036,527

ROTARY DEVICE WITH ACCESS PORT Filed Oct. 20, 1960 FIG. I

INVENTOR. E. F. PETERSON ATTORNEY United States Patent ()fiice 3,035,527Patented May 29, 1962 3,036,527 ROTARY DEVICE WITH ACCESS PORT Edwin F.Peterson, Martin Engineering Co., Neponset, Ill. Filed Get. 20, 1960,Ser. No. 63,808 8 Claims. (CL 103-136) This invention relates to arotary device, typical of which are fluid pumps, motors, etc., and moreparticularly to improvements residing in the provision of an access portfor inspection and/ or removal of internal parts such as impellermembers, vanes and the like.

A conventional device, motor or pump of the general character referredto is normally constructed in such manner as to have a rotor housingincluding an internal rotor chamber, the housing having an annular walland a pair of opposite radial side walls respectively presenting aninternal circumferential surface and a pair of radial surfaces definingthe chamber. A rotor within the chamber is mounted on a shaft forrotation on an axis normal to the radial surfaces and such rotor willcarry one or more vanes or equivalent in power members adapted to travelin such manner that their respective end edges operate in contact withthe interior chamber surfaces. These surfaces and the respective edgesof the vanes are accurately machined, ground and lapped so thatsubstantially a fluid-tight sealing relationship exists among the edgesand surfaces so that the pump or motor will operate at its highestdegree of efficiency. As part of the precision built into a pump ormotor of this character, the rotor shaft is journaled on precisionbearings and high-quality seals and gaskets are employed. The assemblyis normally of three-piece construction, in which the annular wall issandwiched between the two side walls and suitable removable securingmeans are utilized to hold the assembly together.

It is a characteristic of many motors or pumps of this character that atrelatively frequent intervals inspection of the internal parts is inorder, mainly as a precautionary measure to determine the existingconditions of the vanes. Heretofore, such inspection has required theremoval of one of the side walls or plates, and thi necessarily entailsdisturbing the gaskets and bearings, and great care must be exercised indisassembly and reassembly in order to maintain the precisioncharacteristics of the device. According to the present invention, thisdisadvantage is eliminated by the provision in one of the side walls orplates of an access port having a removable closure member, and thisaccess port is of such size and location as to be laterally registrablewith a position through which the successive vanes will travel as therotor is rotated. More specifically, the port, which may conveniently beformed as a cylindrical bore, has a diameter slightly larger than theradial dimension of the impeller members or vanes. Hence, when theclosure element is removed and the rotor turned by hand, the vanes willsuccessively appear at the port and inspection thereof can be made fromoutside the housing without removal of any of the basic housingcomponents. Moreover, if it is necessary to remove a vane, the same maybe withdrawn endwise from its pocket in the rotor via the access port.

A still further feature resides in the provision on the closure memberof an inner face so fashioned as to lie flush with the inner radial faceof the side wall in which the port is formed, whereby the inner face ofthe closure member forms a continuation of this radial wall withoutinterruption, thereby presenting no abrupt edges to interfere withoperation of the vanes as their respective end edges travel over thisradial surface. In this regard, it is a significant feature of theinvention to provide cooperative abutment means limiting inwardpositioning of the closure element to a condition in which the innerface is flush with the radial surface as aforesaid. In one form of theinvention, the port is so arranged that a portion of the annular walloverlaps a segment of the port so that the inner face of the closureelement abuts the overlapping portion. In another form of the invention,the port has at an external portion thereof a counterbore forming anannular recess in which seats an annular shoulder on the closureelement. In both cases, removable securing means are provided foraccurately positioning and holding the closure element in place. In oneform of the invention, the securing means includes biasing means forholding the closure member in its normal position with the abutmentmeans in cooperative relationship. In both forms of the invention, theremovable means includes an end plate which also provides access to thebearing for the shaft in the proximate side wall.

The foregoing and other important objects and desirable featuresinherent in and encompassed by the invention will become apparent aspreferred embodiments of the invention are described by way of examplein the ensuing description and accompanying sheet of drawings, thefigures of which are described below.

FIGURE 1 is a sectional view through a rotary device, such as a pump ormotor, employing one form of invention.

FIGURE 2 is a section on the line 2--2 of FIGURE 1.

FIGURE 3 is an end View of the device shown in FIGURES 1 and 2, with aportion thereof broken away.

FIGURE 4 is a fragmentary section of a modified form of the invention.

FIGURE 5 is a fragmentary end view of the structure shown in FIGURE 4.

In the drawing, the rotary device may be taken as a typical constructionrepresentative of a fluid pump or motor, which comprises essentially arotor housing 10 having an annular or circumferential wall 112sandwiched between a base member or plate 14 and a radial side wall 16.These three components afford a cylindrical rotor chamber 18 which has acircumferential interior surface 20 and a pair of radial interiorsurfaces 22 and 24 afforded respectively by the circumferential andradial walls 12, 14 and 16. The radial walls 22 and 24 are of coursenormal to the cylinder of the wall 20, and the walls 14 and 16 areappropriately recessed respectively at 26 and 28 to carry bearings 30and 32 for journaling a rotor shaft 34 which is rotatable on an axisperpendicular to the radial planes of the walls 22 and 24 and which isslightly eccentric as respects the true center of the circumferentialwall 20. The shaft 24 may be driven by any suitable means, not shown, tocause operation of the pump or motor, which includes the provision of arotor 36 keyed or otherwise fixed to the shaft 34 within the chamber 18.

The rotor 36 has therein a plurality of uniformly circumferentiallyspaced pockets or slots 38, each of which opens radially outwardly tothe interior circumferential wall 20 and each of which also opensendwise respectively to the interior radial walls 22 and 24. Each slotcarries therein a vane or equivalent impeller member 40, each of whichhas its radially outermost edge 42 adapted to travel over and in closecontact with the circumferential wall 20 and each of which has oppositeend edges 44 and 46 adapted to travel over and in close contactrespectively with the interior radial walls 22 and 24. It is at thispoint that the parts are precision formed so that an effective fluidseal is provided between each surface and its respective cooperatingedge of the vane. As is conventional, the vanes are urged outwardly bycentrifugal force or otherwise as the rotor rotates and the transfer offluid under pressure is accomplished via fluid inlet and outlet passages48 and 50 formed in the housing.

s a es? Because of the aforesaid desirability of inspecting the internalpart of the motor or pump without requiring disassembly, as by removalof the several cap screws 52, for example, that hold the parts together,there is provided in the radial wall 16 an access port or bore 54, whichis here shown as having a diameter slightly in excess of the radialdimension of a vane 40. This port is of course eccentric to the axis ofthe shaft 34 and opens to the chamber 18 in such location that it is inlateral register with a position past which the vanes 40 successivelypass as the rotor turns. This is best illustrated in FIGURES 1 and 2,wherein it will be seen that the lower vane 40 is in register with theport 54. Since this vane is relatively loosely carried in its slot orpocket 38, it may be removed endwise from the rotor slot via the port 54for inspection 'and/ or replacement.

The port 54 normally carries a closure element in the form of acylindrical plug 56 which has a cylindrical outer surfaceprecision-formed to fit the cylindrical bore or port, and which furtherhas an inner radial face 58 likewise precision-formed so that when it isnormally in position the face 58 lies perfectly flush with the interiorradial face 24, leaving no interruptions to interfere with smooth travelof the end edges of the vanes over that surface. To insure thatinstallation of the plug 56 always presents the inner face 58 thereofexactly in the plane of the interior radial surface 24, cooperativeabutment means is provided, in this form of the invention comprisingcooperating parts 60 and 62 respectively on the wall 12 and on the plug56-. The part 60 of the wall 12 comprises a portion of the wall thatoverlaps a segmental portion of the port 54. The diameter of the portand plug are sufiiciently in excess of the radial dimension of the vanes40 as to permit the relationship just described. Accordingly, when theplug 58 is installed, the portions 60 and 62 will cooperate in themanner just described. In original machining, the plug may be installedand the surfaces 24 and '58 accurately machined at the same time. As theedges of the vanes and the surface 2458 wear during use of the pump ormotor, it is expected that the wear will be evenly distributed and thecoplanar relationship will continue to exist. Because of the precisionmachining of the plug and port, an effective fluid-tight relationship isestablished.

The plug 56 is normally maintained in position by securing means, heretaking the form of an end plate 64 having releasable securing means inthe form of screws 66 and additional cap screws 68 for securing theplate removably to the outer face of the radial wall 16. This plate hasone portion 70 thereof radially overlapping the bore 28 in which thebearing 32 is carried and it further has another portion 72 overlappingthe area in which the port 54 is formed. The interior part of the platein its portion 70 has an annular integral portion 74 which abuts theouter radial face of the bearing 32.

The plate portion 72 has on its interior portion a pilot stud 76 againstwhich seats one end of biasing means in the form of a compression spring78. The outer portion of the plug 56 is coaxially recessed to receivethe other end of the spring 78. Thus, the spring acts against the plugand reacts against the wall portion 74 to normally maintain the plug 56in its normal condition in which the face 58 is coplanar with the radialsurface 24. The outer end of the plug 56 is counterbored and tapped at80 so that a threaded tool may be inserted into the plug forfacilitating withdrawal thereof after the plate 70 and spring 78 areremoved. When the plate is removed, access is also available to thebearing 32, as well as to the interior of the rotor housing when theplug is withdrawn, and the rotor may be turned by hand so thatsuccessive vanes occur in register with the port 54, through which portthese vanes may be individually drawn for inspection and/or replacement.The access port and its associated components 56 and 70 thus enableinspection and replacement of the vanes without requiring a majorassembly of the device. Consequently, the basic components of the devicemay remain in place and cooperating sealing surf-aces and bearingalignment will not be disturbed.

That form of the invention shown in FIGURES 4 and 5 partakes of theadvantages of the form just described, but employs a different form ofport and closure construction. Accordingly, basic components of thedevice that are the same as those illustrated in FIGURES l, 2 and 3 willbear the same reference characters. These are employed to designate thecircumferential wall 12 having the circumferential interior surface 20,the radial wall 16 having the interior radial surface 24, shaft 30,bearing 32 and vanes 40. In this case, the radial wall has an accessport 154 normally closed by a closure element or plug 156, the innerradial face 158 of which is fashioned to lie exactly coplanar with theinterior radial wall surface 24. There is in this case no radial offsetor overlap between the interior circumferential surface 2%) and thecircumference of the port 54, in which case a different form ofcooperative abutment means is relied upon. Here, the wall 16, in itsarea at the outer end of the port 154, has therein an annular recess 160and the plug 156 has thereon an accurately machined annular shoulder 162which fits within this recess so that the inward position of the plug156 is correctly established to maintain the perfect coplanarrelationship between the surface 24 and face 156, for the same purposeas that described in connection with FIGURES 1, 2 and 3.

The end plate or cover which corresponds to the cover 64 in FIGURES 1, 2and 3 is here designated by the numeral 164 and is shown as havingportions 179 and 172 respectively overlapping the bearing 32 and thearea of the outer end of the plug 156. Here again, securing means suchas cap screws and additional screws may be employed, as at 68. As meansfor securing the inward position of the plug 156, the plate portion 172is coaxially drilled and tapped at 176 to carry a threaded element inthe form of a set screw :178 which coaxially seats against the outer endof the plug 156. Except for the difference just described, the form ofthe invention shown in FIGURES 4 and 5 performs the same functions asthat described in connection with FIGURES 1, 2 and 3, and repetition isdeemed unnecessary.

Features and advantages of both forms of the invention, other than thosecategorically pointed out, will readily occur to those versed in theart, as will many modifications and alterations in these forms, all ofwhich will occur to those versed in the art, all without departure fromthe spirit and scope of the invention.

What is claimed is:

l. A rotary device, comprising a housing having a rotor chamberincluding a circumferential wall having an interior circumferentialsurface and a radial wall having an interior radial surface normal tosaid circumferential surface, and said chamber being closed at the sideopposite said radial wall; a rotor shaft extending through the chambergenerally centrally thereof on an axis normal to said radial wall; meansjournaling the shaft in the housing; a rotor fixed to the shaft withinthe chamber and having therein a pocket opening radially to thecircumferential surface and laterally to the radial surface; an impellermember carried in the pocket and having an outer edge portion and aradial edge portion adapted to travel respectively over saidcircumferential and radial surfaces as the rotor rotates; said radialwall having therein an access port on an axis parallel to the rotor axisand of such size and location as to be laterally registrable with theimpeller member at a predetermined angular position of said member inthe chamber, and said member being removably carried in said pocket forendwise withdrawal thereof through said port, said radial wall having asubstantial thickness in its axial dimension in the area of said port soas to give said port a comparable substantial length; a plug element, ofsubstantial axial length having a close sliding fit with the port andinwardly and outwardly slidably carried by and normally closing the portand having an inner end face precision-fashioned to lie flush with saidradial surface, said element having an outer end portion; cooperatingabutment means precision-fashioned respectively on said element and onewall and so dimensioned relative to said inner end face to limit inwardpositioning of said element to a condition in which said end face andradial surface are flush as aforesaid; and securing means for releasablyretaining said element in place with the abutment means in cooperativerelationship, including an end member separate from said element andabutment means and rigidly but removably secured to the radial Wall inoutwardly spaced radially overlapping relation to said element outer endportion, and force-exerting means within the port and cooperativebetween said end member and said outer end portion to act on one andreact on the other substantially at their axial centers to causeengagement of said abutment means with each other.

2. The invention defined in claim 1, in which: yielding saidforce-exerting means comprises biasing means acting on the element tonormally hold same in position with its abutment means cooperating withthe wall abutment means.

3. The invention defined in claim 1, in which: said force-exerting meansincludes screw-threaded means carried by said member and adjustableinwardly for urging the element into position with its abutment meanscooperating with the wall abutment means.

4. The invention defined in claim 1, in which: the abutment meansincludes as one part thereof a portion of the circumferential walldisposed in overlapping relation to the port to partially obstruct saidport at the radial face of said first wall, and, as a second partthereof, a portion of the inner face of said elment normally abuttingsaid one part.

5. The invention defined in claim 1, in which: the abutment meansincludes as one part thereof shoulder means comprising an enlargement ofthe port in said radial wall adjacent to the outer end thereof, and as asecond part thereof, shoulder means on the element normally abuttingsaid first mentioned shoulder means.

6. The invention defined in claim 1, in which: the port is cylindricaland the first wall has at an outer portion thereof an enlargedcounterbore forming with said port an annular shoulder, and the elementis correspondingly cylindrical and has thereon an annular shoulderfitting said counterbore in normally abutting relationship, saidcounterbore and said shoulder comprising the aforesaid abutment means.

7. The invention defined in claim 1, in which: the shaftjournaling meansincludes a bearing in said radial wall; and the outer end memberincludes a portion radially overlapping the bearing so that removal ofsaid member exposes said bearing simultaneously with exposure of saidelement.

8. The invention defined in claim 7, in which: the outer end member isin the form of a plate, and said force-exerting means includes a portionaccessible from outside said plate for adjustment thereof to vary itsaction axially inwardly on the element.

Dale et a1. June 16, 1953 Thomas et al. Feb. 12, 1957

